The invention relates generally to antennas for vehicles and particularly to the provision of global positioning system and radio functions in a vehicle.
There is an increasing interest in providing global position system (GPS) receivers in motor vehicles. With the GPS system, a driver may not only receive position information from the satellite positioning system, but he or she may also receive an indication on a map of his or her current position. Additional navigation functions may also be provided such that global positioning technology can provide the driver with a relatively advanced functionality at a very reasonable price.
There is also increasing interest in in-car personal computer systems. These systems may include a processor which may provide a number of traditional computer functions together with additional functions adapted to the motor vehicle, such as GPS or navigation functions. Thus, it is necessary to provide appropriate antennas for implementing these functions.
Today there are two common types of GPS antennas. With the active element, the antenna element is generally a flat planar structure and with active electronics. The passive structure is simpler to implement, but has some drawbacks with respect to quality. Since power must be supplied to active GPS antennas, the cabling is usually thicker.
One approach to providing GPS antennas in motor vehicles is simply to mount the antenna on top of the vehicle. However, this generally requires cutting a hole through the body of the vehicle for the passage of wires. This may be undesirable to many users who may not prefer to cut holes in their cars and the protruding antenna may interfere with the vehicle body lines creating a less desirable appearance.
It is also possible to cut a hole in the body of the vehicle, for example, at the trunk, add a mounting bracket and a GPS antenna below the hole. The hole then can be filled with an appropriate filler. Again, the vehicle body is permanently compromised. Moreover, the antenna does not have a full view of the sky and therefore, its operation may be adversely affected.
Still another approach is to put the GPS antenna in the center brake light enclosure or in the rear spoiler. However, this is only possible with car designs which are amenable to this configuration and again, they do not provide a full view of the sky.
Thus, there is a continuing need for an effective and desirable way to mount GPS antennas on motor vehicles.